Composition material for friction elements or the like



Aug. 13, 1940. R. E. sPoKEs 2,211,354

COMPOSITION MATERIAL FOR FRICTION ELEMENTS OR THE LIKE Filed Feb. lf3.v 1937 Patented Aug. i3, 1940 2,211,354

UNITED STATES PATENT OFFICE COMPOSITION MATERIAL FOR FRICTION ELEMENTS OB. THE LIKE Application February 18, 1937, Serial No. 126,406

3 Claims. (Gl, 188.254)

'Ihis invention relates to composition matetion elements or thenlike in accordance with rials for friction elements or the like and the this invention are those included in the vermisalient object is to insure against separation of culite group. This group comprises la number such material from the means or members in of micaceous minerals, all hydrated silicates.

5 which it is mounted in use. varying somewhat in composition. They are In the patent to Gallagher and Jones 1,082,266 alteration products chiefly of the micas. Many there is shown a friction element-in the form of are more or less of an indefinite chemical nature a brake shoe suitable for use in railway equipand the composition variesl with that of the ment. As there shown the element includes an original mineral and the degree of alteration.

external metallic shell or casing which contains Heated to 100 F. to 110 F. or dried over sull0 a filler of composition material and the present Dhurie acid. mOSt Substances of the vermiculite invention relates to a composition material group lose considerable water, for example, as adapted for use as the filler in a shell such as much as ten percent.A Further water is given off that disclosed in the aforesaid patent. This inwhen substances of the vermiculite group are vention, however,.is not only adapted for use subjected t0 higher temperatures. All such subl5 with a shell such as that disclosed in the -aforestances have the physical characteristic of exsaid Gallagher and Jones patent but is applifoliation; some of the substances particularly cable in a wide variety of uses. Thus, for exshowing this characteristic to a marked degree. ample, in my Patent No. 2,114,037 vgranted April S10W1y Opening Out, When heated gradually. lrltO 12, 1933, a p1ug or a closure is shown which is long worm-like threads. 'I'he substances in- 20 suitable for use with a friction element to close eluded in this group are I10t entirely distinct the openings therein through'which fastening Species and may best be identied by their means employed to secure such an element in names, amOhg Which may be Cited leffersite, position are extended, and a plug or closure ac- Culsageeite. kerrite, lennilite, hallite, philadelcording to the invention of that application may phite. Vaalite. maconite, dudleyite. pyrasehlerite 25 be advantageously made of the composition maand also the substance which is known as vermieterial to which this invention pertains. lllite- The composition material of this invention is Another substance which is suitable for this for use in those instances whore it will be coninvention is stilbite (Desmine), a typical formula fined, Thus, for exampIe, the material may be for which 1S (H4(Na2Ca)A12SieOis+4I-I2O). This 30 confined in a shell like that shown in the above substance occurs mostly in cavities in amygreferred to Gallagher and Jones patent or in daloidal basalt and similar rocks, and also in the fastening means openings of a friction elesome metalliferous veins and in granite. mont in accordance with the invention of my A substance selected from the vermiculite patent or otherwise, and another important obgroup 01 Stilbite may be used in a Wide Variety 35 ject of my invention is to provide a nove] oomof composition materials for friction elements or position material which will remain in position the like but by Way of illustration of my inven- Whon oonflned in use and an ancillary object tion a formula for a composition friction mateis to provide a material which will expand when rial suitable for use in a shell such as that shown subjected to heat as, for example, the heat genin the Gallagher and Jones Patent 1,082,266 or 40 erated in the use of a friction element whereby from Which plugs or closures, such as are dissuch expansion may be relied upon to insure reclosed in my Patent No. 2,114,037, may be made tention of the confined material in the position and which is suitable for other usages is as folin which it is mounted in use. lows:

A further object is to incorporate in a com- Pari-,S by Weight 45 position material suitable for friction elements Smoke sheet rubber 10 or the like one or more substances which will Sulphur 3 expand when subjected to heat, and a Still fur- Carbon black 10 ther object is to employ one or more substances Barytes 15 which, while expandible when subjected to heat, Phenol formaldehyde resin 6 5o will not upon expansion detrimentally disrupt Short fiber asbestos 20 the internal structure of the composition mate- Litharge 2 11 laelfirtlon element ,0? the like made from Anyof the substances included in the vermic- In the accompanying drawing a perspective ulite group or stilbite may be included in the 55 view of a railway brake shoe, I have illustrated a typical use to which the novel composition of this invention may be put.

Among the heat-expandible substances which oo may be used in composition material for fricabove formula and this is done by using substantially ninety parts by weight of the composition of the above formula along with substantially ten parts by Weight of the substance known as vermiculite or other substance selected from the vermiculite group or stilbite. Furthermore, combinations of two or more such substances may be used in a ratio relative to a composition material somewhat like that Just specified. It is also to be noted that vermiculite or other substance selected from the vermiculite group or stilbite or combinations of such substances may be used in other composition materials suitable for use in friction elements or the like and in such circumstances the substances are preferably used in a ratio of substantially ten parts by weight of the substance-relative to ninety parts by weight of the composition material.

The above ratio is maintained in those instances where the product is not to be subjected to temperatures of more than 600 F. for in such instances it may be desirable to reduce the ratio to five parts by Weight of vermiculite or the like to ninety-five parts by weight of the composition material for so to do reduces the likelihood of disruption of the internal structure of the product upon exfoliation of the heat-expandible substance when the product is subjected to heat in use.

When heat-expandible substances are mixed in a composition material in a ratio substantially like that above specified, the mixture or a product made therefrom when subjected to heat, as for example, the heat generated in the use of a friction element made of the mixture, will be tightly secured in the carrier therefor or a plug or closure made of this mi'xture and used in the manner described in my aforesaid co-pending application will tightly bind in the opening in which it is mounted. The tight securance of the mixture of a product made therefrom in the carrier or the aforesaid binding in the opening will result by reason of the exfoliation of the substance, such as vermiculite, included in the material, for such exfoliation will result in an expansion of the mixture or material and it is obvious that when the material expands, but is confined, a firm anchorage of the material will result.

When plugs such as those described in my aforesaid Patent No. 2,114,037 are made of the composition material like that of the foregoing formula and a heat-expandible substance is included, the plugs are preferably subjected to a short cure of, for example, thirty minutes at a temperature of 290 F., and when a filler for a shell such as that shown in the aforesaid Gallagher and Jones patent is made of the composition material like that of the above formula it is also preferably cured, the time of cure and temperature employed depending upon the size of the filler and being proportionate to the time involved to cure plugs for use in accordance Awith my aforesaid co-pending application. A short cure is preferably utilized to avoid undue exfoliation of the substance such as vermiculite so that exfoliation of this substance will not be completed until the composition material is confined and subjected to heat.

When a substance such as vermiculite is used in a ratio relative to the other ingredients of a composition material in a ratio substantially like that above specified, which is to say, in a ratio of from five percent to ten percent, the exfoliation of the substance does not disrupt the internal structure of the article formed from the composition, and in each instance where a substance such as vermiculite is employed along with other ingredients in la composition material in which expansion in use is desirable, care should be taken to keep the quantity of the substance, such as vermiculite, below that which might result in disruption of the internal structure of the article.

made from the composition.

By Way of further describing my invention, I have shown in the accompanying drawing a railway brake shoe of the character disclosed in the aforesaid Gallagher and Jones Patent No. 1,082,266 and which preferably comprises a metallic shell I of a longitudinal and transverse configuration conventional in railway brake shoes. The shell I has a center attaching lug 2 on the back midway between the ends thereof and the usual end stops 3 on its back at the ends thereof, these parts being constructed and arranged for cooperation with cooperating parts on a conventional brake head to which the shell I may be attached by the usual removable key or the like.

'Ihe shell I is filled with composition friction material, indicated by 4, ,that is exposed at the open face of the shell and which is of the character hereinabove described whereby, by reason of the property of exfoliation possessed by one or more of the substances included in the composition material, the material 4 is tightly retained in the shell I as hereinabove explained.

The preferred form of my invention has been described but it is to be understood that this is capable of variation and modification and I am, therefore, not to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall Within the purview of the following claims.

I claim:

1. A friction element including a body provided With an opening for the reception of a fastening element, said opening containing a plug of friction material and said friction material containing not substantially less than five percent (5%) nor substantially more than ten percent (10%), by weight of said friction material, of one or more minerals selected from the group consisting of the vermiculite family of minerals and stilbite.

2. A friction element including a casing containing a filler of friction material and said friction material containing not substantially less than ve percent (5%) nor substantially more than ten percent (10%), by weight of said friction material, of one or more substances selected from the group consisting of the vermiculite family of minerals and stilbite.

3. A friction element embodying friction material and said friction material containing not substantially less than five percent (5%) nor substantially more than ten percent (10% by weight of said friction material, of one or more substances selected from the group consisting of the vermiculite family of minerals and stilbite.

RAY E. SPOKES. 

